Adjusting means



March 9, c 5 CRAKE ET A ADJUSTING MEANS Filed Nov. 20, 1934 s Sheets-Sheet 2 JZYUEHTURS.

DHHEYS.

.5. CHAI1'ES& AIfEIS.. BY 16% T March 9, 1937. c. s. CRAKES ET AL ADJUSTING MEANS Filed Nov. 20, 1934 3 Sheets-Sheet I5 ZUQOCCIIV HdmuHrmn DWWOJU XN &. 8% a E m V T RR M BM 25 Patented Main 9, 1937 ADJUSTING MEANS Clarence S. Crakes and Frank W. Crakes, Santa Maria, Calif.

Application November 20, 1934, Serial No. 753,974

1 Claim. (Cl. 74-395) This invention relates to improvements in power brakes and has particular reference to a means for utilizing the compressive force in an internal combustion engine to overcome momentum of a vehicle, or other devices to which the engine may be connected.

A further object is to utilize the standard internal combustion engine to accomplish the braking without materially altering its construction.

A further object is to provide means for eliminating gasoline consumption, while coasting or braking.

A still further object is to produce a device which may be caused to function without requiring any additional manual control on the part of the operator of the vehicle.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Fig. 1 is a diagrammatic top plan view of a conventional engine illustrating our device attached thereto,

Fig. 2 is a vertical sectional view of an internal combustion engine showing the cam shaft arrangement,

Fig. 3 is an enlarged cross sectional view on the'line 3-3 of Fig. 1,

Fig. 4 is a fragmentary plan view of the exhaust cam driving gear,

Fig. 5 is a cross sectional view taken on the line 5-5 of Fig. 4, showing the cam advancing mechanism,

Figs. 6, 7, 8 and 9 are diagrammatic views showing the manner in which the exhaust cam is moved to produce the braking operation of the motor, and Figs. 10, 11, 12 and 13 illustrate the cycle of operation of both normal power and braking cycles of the motor.

It is common practice when coasting to employ the compression of an engine in order to 15 slow down or brake the momentum of the car.

There is under normal conditions a small charge which is being exploded in the engine and, therefore, there is not a full braking action, and further, the opening of the valves are not properly timed to produce a braking effect, even if the ignition were turned off. Applicants have, therefore, devised a means for controlling the action of the exhaust valve so as to cause a compressive action in a four-cycle engine at each upstroke of the piston.

In the accompanying drawings wherein for the purpose of illustration is shown a preferred em.- bodiment of our invention, the numeral 5 designates an engine of any desired type and in the particular showing overhead exhaust and intake 5 rocker arms 6 and 1 are shown. The intake rocker arms are actuated by push rods 8 which are in turn moved by the cam shaft 9 having cams ll formed thereon. The rocker arm 6 is, of course, connected to the intake valve so as to open the same in the manner which is well known.

Our invention consists in providing a second cam shaft l2 having cams l3 which engage push rods M, which push rods in turn engage the rocker arm 6, which rocker arm in turn actuates the exhaust valves. Referring to Fig. 2 it will be noted that a piston is designated as at It which is connected to the crank shaft I! by the customary connecting rod I3. I have shown an intake manifold at l9, which is connected to the usual carburetor and has a rotary valve 2i positioned' therein, which is actuated by a pull rod 22 and lever 23. This rotary valve permits the flow of gas to the engine from the carburetor 25 pipe 24 when in the position shown in Fig. 3. When, however, it is turned a quarter turn, the manifold will then be connected through the port 26 to the atmosphere and the carburetor pipe 24 will be entirely cut off. The customary 30 brake pedal is shown at 2'! which is connected by a pull rod 28 to a fork 29, the purpose of which will be later seen. A similar pull rod 3! is connected to a crank arm 32 formed upon the rod 33 and through a crank arm 34 con- 35 nects to the pull rod 22.

Referring now to Figs. 4 and 5, it will be noted that the cam shaft i2 is keyed as at 36 to a barrel-shaped member 31 having a spiral slot 38 formed therethrough. Freely rotatable on this 40 barrel-like member is a tubular member 39 and retained against length-wise movement by a shoulder 4| and a threaded nut 42. This tubular member 39 carries a flange 43 to which the driving gear 44 is secured. This driving gear meshes 45 with the customary cam gear of the engine. A spring 46 surrounds the tubular member and bears against the flange 43 at one end and against a collar member 41 at its oposite end. This collar 41 is slidable on the tubular member 39 and engages the ends of a pin 48 extending through i the tubular member and barrel-shaped member. This tubular member 39 also has a spiral slot 49 formed therein. A thrust bearing is shown at tarding as the case may be of the cam shaft i2 and consequently the action of the exhaust valves controlled thereby. At the same time this action is taking place, the pull rod 3| has acted through its connections to cut off the flow of gas to the engine by moving the rotary valve 2| so that the supply of gas to the engine is stopped and the manifold is then connected directly to the atmosphere.

In order to illustrate the action Within the engine, under these conditions, we have illustrated in Figs. 6, 7, 8 and 9, the various positions of the valves of an engine and we have shown the cam of the exhaust valve in both full and dotted line positions. The dotted line position shows the position the exhaust valves will assume when power is being produced, and the solid lines indicating the exhaust cams, show the position in which the exhaust valves will open and close when the engine is acting as a power absorber.

By viewing Figs. 10, 11, 12 and 13, the operation may be very readily explained. Referring to the top line of the figures, it will be noted that the intake on the power cycle consists in the sucking in by the downward movement of the piston, a charge, the intake valve remaining open until the piston is moved past bottom center. Referring now to the top portion of Fig. 11, it will be noted that the intake valve has closed, the piston is moving up and compressing until top dead center is reached at which time the charge is exploded and we have the power stroke as indicated in the upper portion of Fig. 12, the exhaust valve opening just before the piston has reached the bottom center and the remainder of the revolution as indicated in the upper portion of Fig. 13, is an exhaust period. Referring now to the bottom portions of Figs. 10, 11, 12 and 13, it will be noted that the period of intake is the same as that in the power cycle, the only difference being that when the intake valve is open only pure air is sucked in during the downward movement of the piston. In the lower portion of Fig. 11, this air is shown as being compressed until the piston reaches top center, at which time the exhaust valve will open, the compressed air being released and immediately fresh air drawn in as the piston moves downwardly as illustrated in the lower portion of Fig. 12. In other words instead of firing as shown in the upper portion of this figure, the exhaust valve is held open to a point past bottom center so that fresh air is drawn in and is ready to be compressed as shown in the bottom of Fig. 13. Consequently when the piston moves upwardly this air is again compressed until the piston reaches top center and the intake valve opens, allowing the air to escape to the atmosphere and at this time the cycle starts all over again.

t will thus be seen that we have devised a means whereby a full compression may be secured at each stroke of a four cycle engine. It is, of course, obvious that by only rotating the cam shaft I2 a portion of its possible angular displacement will result in a partial braking and that with this system it is possible to gradually apply the braking effect up until maximum has been reached.

It is to be understood that the form of our invention herewith shown and described is to be taken as a preferred example of the same and that various changes relative to the material, size, shape and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claim.

Having thus described our invention, we claim:-

In a device for advancing or retarding a revolving shaft comprising a cylindrical member secured to said revolving shaft, a spiral slot formed in said cylindrical member, a tubular mem er surrounding said cylindrical member and freely rotatable thereon, said tubular member having a spiral slot formed therethrough, said slot being spiralled in a direction reversed to that in the first mentioned spiral, means for rotating said tubular member, a pin extending through said slots formed in said tubular member and said cylindrical member and having its ends secured in a slidable collar longitudinally movable on said tubular member, means for moving said collar longitudinally from a remote point, and spring means for returning said collar to its normal running position.

CLARENCE S. CRAKES.

FRANK W. CRAKES. 

